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V₁, a water-soluble portion of vacuole-type ATPase (V-ATPase), is an ATP-driven rotary motor, similar to F₁-ATPase. Hydrolysis of ATP is coupled to unidirectional rotation of the central rotor D and F subunits relative to the A₃B₃ cylinder. In this study, we analyzed the rotation kinetics of V₁ in detail. At low ATP concentrations, the D subunit rotated stepwise, pausing every 120°. The dwell time between steps revealed that V₁ consumes one ATP per 120° step. V₁ generated torque of ≈35 pN nm, slightly lower than the ≈46 pN nm measured for F₁. Noticeably, the angles for both ATP cleavage and binding were apparently the same in V₁, in sharp contrast to F₁, which cleaves ATP at 80° posterior to the binding of ATP. Thus, the mechanochemical cycle of V₁ has marked differences to that of F₁.